instrument / gauges reading wrong

Wondering if anyone has had this issue and what was the solution. replaced alternator a few weeks ago. Mb the dash voltage is derived from the alternator connections. The oil gauge is at max and the temp is high and the voltage reading is low. I assume it is a connection or voltage regulation to the gauges......... anyway i will diagnose it and repost unless someone here may have already had a similar problem and would be kind enough to share the knowlege.

Thanks

mpyrol

Poor grounding at motor / battery connection turned out to be the culprit.